Sometimes we have a major break through which is not just another small step-by-step improvement. I would say that a singularity in AI means a major break through e.g. Artificial General Intelligence (AGI). GPT-3 is a big step forward, but it's not an AGI and therefore not a singularity (major break through). But of course many small step-by-step improvements are required for a major break through, it doesn't drop out of thin air.